<template>
    <div class="login_container">
        <div class="login_box">
            <!-- 头像区域 -->
            <div class="avatar_box">
                <img src="../assets/logo.png" alt="">
            </div>
            <!-- 登录表单区域 -->
            <el-form label-width="0px" ref="loginFormRef" class="login_form" :model="loginForm" :rules="loginFormRules">
                <!-- 用户名 -->
                <el-form-item prop="username">
                    <el-input prefix-icon="el-icon-user" v-model="loginForm.username"></el-input>
                </el-form-item>
                <!-- 密码 -->
                <el-form-item prop="password">
                    <el-input prefix-icon="el-icon-lock" v-model="loginForm.password" type="password"></el-input>
                </el-form-item>
                <el-form-item class="btns">
                    <el-button type="primary" @click="login">登录</el-button>
                    <el-button type="info" @click="resetLoginForm">重置</el-button>
                </el-form-item>
            </el-form>
        </div>
    </div>
</template>

<script>
export default {
  data () {
    return {
    // 这是登录表单的数据绑定对象
      loginForm: {
        username: 'admin',
        password: '123456'
      },
      loginFormRules: {
        username: [
          { required: true, message: '请输入用户名', trigger: 'blur' },
          { min: 3, max: 10, message: '长度在3-5个字符之间', trigger: 'blur' }
        ],
        password: [
          { required: true, message: '请输入密码', trigger: 'blur' },
          { min: 6, max: 15, message: '长度在6-15个字符之间', trigger: 'blur' }
        ]
      }
    }
  },
  methods: {
    resetLoginForm () {
      this.$refs.loginFormRef.resetFields()
    },
    login () {
      this.$refs.loginFormRef.validate(async valid => {
        if (!valid) return
        const { data: res } = await this.$http.post('login', this.loginForm)
        if (res.meta.status !== 200) return this.$message.error('用户名或密码输入错误！')
        this.$message.success('恭喜你，登录成功！')
        // 1. 将登录成功之后的 token，保存到客户端的 sessionStorage 中
        //   1.1 项目中出了登录之外的其他API接口，必须在登录之后才能访问
        //   1.2 token 只应在当前网站打开期间生效，所以将 token 保存在 sessionStorage 中
        window.sessionStorage.setItem('token', res.data.token)
        // 2. 通过编程式导航跳转到后台主页，路由地址是 /home
        this.$router.push('/home')
      })
    }
  }
}

</script>
<style lang="less" scoped>
.login_container {
    background-color: #2b4b6b;
    height: 100%;
}
.login_box {
    width: 450px;
    height: 300px;
    background-color: #fff;
    border-radius: 5px;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);

    .avatar_box {
        position: absolute;
        left: 50%;
        transform: translate(-50%, -50%);
        width: 130px;
        height: 130px;
        border: 1px solid #eee;
        border-radius: 50%;
        padding: 8px;
        box-shadow: 0 0 10px #ddd;
        background-color: #fff;
        img {
            height: 100%;
            width: 100%;
            border-radius: 50%;
            background-color: #eee;
        }
    }
}

.login_form {
    position: absolute;
    bottom: 0;
    width: 100%;
    padding: 5px 20px;
    box-sizing: border-box;
}

.btns {
    display: flex;
    justify-content: flex-end;
}
</style>
